Lancing devices are utilized for penetrating the skin of a human or animal subject at a lancing site to obtain a sample of blood or other body fluid for medical testing, as in blood-typing or blood-glucose testing. Known lancing devices commonly include a housing containing a drive mechanism, a charging mechanism for energizing the spring or other biasing means of the drive mechanism, and a release mechanism for releasing the drive mechanism upon actuation. A lancet is typically propelled by the drive mechanism from a retracted position within the housing to an extended position wherein a sharp tip portion of the lancet projects from the housing to prick the subject's skin at a desired lancing site.
Lancing devices are available in multi-use and disposable designs. In multi-use designs, the lancet is a disposable component that is removably mounted into a receiver or lancet carrier of the drive mechanism. A used lancet is removed from the lancet carrier after sampling for subsequent disposal. An ejection mechanism can optionally be included for discharge of the used lancet from the lancing device. A new, sterile lancet is then replaced into the lancet carrier for further sampling. In disposable designs, the lancet and carrier are an integral part and the lancing device is disposed of after a single use.
A depth-adjustment mechanism can optionally be provided to adjust the penetration depth of the lancet, to control sample size and/or to minimize pain. Known depth-adjustment mechanisms include endcaps that are adjustably positioned relative to the lancing device housing, but they are generally susceptible to accidental and unknowing manipulation to a different depth setting, and they can be difficult to manipulate for people with limited dexterity. Other known depth-adjustment mechanisms include movable stops that limit the travel of the lancet by contact with the lancet carrier, but they generally increase the vibrations and impact force thereby causing more pain to the patient.
Accordingly, it can be seen that needs exist for improvements to depth-adjustment mechanisms for lancing devices. It is to the provision of improved lancing devices and lancing depth-adjustment mechanisms that the present invention is primarily directed.